Evidence that Ca(2+) cycling by the plasma membrane Ca(2+)-ATPase increases the 'excitability' of the extracellular Ca(2+)-sensing receptor.
AuthorsDe Luisi A, Hofer AM
JournalJ Cell Sci
PubMed ID12640037
'The extracellular Ca(2+)-sensing receptor (CaR) is a widely expressed G-protein-coupled receptor that translates information about [Ca(2+)] in the extracellular milieu to the interior of the cell, usually via intracellular Ca(2+) signaling pathways. Using fura-2 imaging of cytoplasmic [Ca(2+)], we observed that HEK293 cells expressing CaR oscillated readily under conditions permissive ... More
Quantification of calcium signal transmission from sarco-endoplasmic reticulum to the mitochondria.
AuthorsPacher P, Csordás P, Schneider T, Hajnóczky G
JournalJ Physiol
PubMed ID11118489
'Recent studies have shown that ryanodine and IP3 receptor (RyR/IP3R)-mediated cytosolic Ca2+ signals propagate to the mitochondria, initiating chains of events vital in the regulation of different cellular functions. However, the fraction of released Ca2+ utilized by the mitochondria during these processes has not been quantified. To measure the amount ... More
Measuring cytosolic Ca2+ in cells with fluorescent probes: an aid to understanding cell pathophysiology.
AuthorsHayes A, Cody SH, Williams DA
JournalInt Rev Exp Pathol
PubMed ID8860943
Detection of changes in near-membrane Ca2+ concentration using a novel membrane-associated Ca2+ indicator.
AuthorsEtter EF, Kuhn MA, Fay FS
JournalJ Biol Chem
PubMed ID8144515
A Ca2+ indicator has been synthesized and characterized which can be used to monitor rapid changes in the free Ca2+ concentration ([Ca2+]) immediately adjacent to cell membranes. This indicator, referred to as C18-Fura-2, consists of a Fura-2 molecule conjugated to a lipophilic alkyl chain which will insert into cell membranes. ... More
A modified confocal laser scanning microscope allows fast ultraviolet ratio imaging of intracellular Ca2+ activity using Fura-2.
AuthorsNitschke R, Wilhelm S, Borlinghaus R, Leipziger J, Bindels R, Greger R
JournalPflugers Arch
PubMed ID9049152
A confocal, ultraviolet laser scanning microscope (LSM) for reliable ratio measurements of localized intracellular Ca2+ gradients using the Ca2+-sensitive dye Fura-2 was developed. In a commercial LSM, the filter wheels for the excitation band-pass filters and the grey filters were replaced by acousto-optic tunable filters (AOTF) for rapid switching (</=1.5 ... More
A spirochete surface protein uncouples store-operated calcium channels in fibroblasts: a novel cytotoxic mechanism.
AuthorsWang Q, Ko KS, Kapus A, McCulloch CA, Ellen RP
JournalJ Biol Chem
PubMed ID11312269
The cytotoxicity of infectious agents can be mediated by disruption of calcium signaling in target cells. Outer membrane proteins of the spirochete Treponema denticola, a periodontal pathogen, inhibit agonist-induced Ca(2+) release from internal stores in gingival fibroblasts, but the mechanism is not defined. We determined here that the major surface ... More
Cell-cell adhesion in human fibroblasts requires calcium signaling.
AuthorsKo KS, Arora PD, Bhide V, Chen A, McCulloch CA
JournalJ Cell Sci
PubMed ID11228159
In connective tissues, intercellular adhesion is essential for tissue morphogenesis, development and wound healing. However, the signaling mechanisms initiated by cell-cell adhesion in fibroblasts and that regulate it are not known. In this study we tested the hypothesis that intracellular calcium signaling is required to mediate intercellular adhesion between fibroblasts. ... More
Calcium signal transmission between ryanodine receptors and mitochondria.
AuthorsSzalai G, Csordás G, Hantash BM, Thomas AP, Hajnóczky G
JournalJ Biol Chem
PubMed ID10809765
Control of energy metabolism by increases of mitochondrial matrix [Ca(2+)] ([Ca(2+)](m)) may represent a fundamental mechanism to meet the ATP demand imposed by heart contractions, but the machinery underlying propagation of [Ca(2+)] signals from ryanodine receptor Ca(2+) release channels (RyR) to the mitochondria remains elusive. Using permeabilized cardiac (H9c2) cells ... More
Inhibition of calmodulin expression prevents low-pH-induced gap junction uncoupling in Xenopus oocytes.
AuthorsPeracchia C, Wang X, Li L, Peracchia LL
JournalPflugers Arch
PubMed ID8584431
The relationship among intracellular pH (pHi), -log10 intracellular Ca2+ concentration (pCai) and gap junctional conductance, the participation of Ca2+ stores, and the role of calmodulin in channel regulation have been studied in Xenopus oocytes, expressing the native connexin (Cx38), exposed to external solutions bubbled with 100% CO2. The time courses ... More